Current solutions for optimizing cellular wireless networks involve a process of gathering network data and processing that data to determine the best possible optimization of network variables to minimize interference. The wireless industry is increasingly focusing on high quality of service, which is a competitive advantage for a wireless service provider. There are several elements to quality of service: coverage, speech quality, network accessibility/capacity, and number of dropped calls, to name a few. To monitor these elements, networks may gather data originating from a number of sources, including drive and/or field testing.
Drive testing is generally the process of driving the roads in a given market with test equipment typically including a laptop computer integrated with a wireless terminal, a GPS receiver and/or a demodulating scanning receiver. Once drive test data is collected, the data is typically provided to post-processing tools which apply various mathematical algorithms to the data to accomplish network planning and optimization. One example of post-processing is automatic frequency planning (“AFP”), where the data is processed to determine the optimal arrangement of frequencies to cell site sectors to minimize network interference. Another post-processing application is automatic cell planning (“ACP”) which analyzes network variables (e.g., frequencies per cell site sector, cell site antenna height, azimuth and/or tilt, cell site sector's transmission power, cell site locations, multipath, and a host of other variables that impact radio frequency propagation) to aid network engineers in making decisions on how best to minimize interference in the network. Service providers and other network operators may also deploy dedicated measurement tools in the network as needed to perform field testing and measurements in response to consumer complaints and other indicators of poor network quality. Field testing equipment may include dedicated hardware deployed to collect measurement data.
As is well known in the art, various wireless protocols exist for defining communications in a mobile network. One such protocol is a time-division multiple access (“TDMA”) protocol, such as the TIA/EIA-136 standard provided by the Telecommunications Industry Association (“TIA”). With TIA/EIA-136 TDMA, each channel carries a frame that is divided into eight time slots (two slots are consumed six time slots to support multiple (3 or 6) mobile units per channel). Other TDMA-based systems include Global System for Mobile (“GSM”) communications systems, which use a TDMA frame divided into eight time slots (or burst periods). GSM has been the European standard and occupies the frequency ranges at 900 MHz and 1800 MHz. The U.S. version of GSM, GSM 1900 operates at 850 MHz and 1.9 GHz. Another exemplary protocol is a code-division multiple access (“CDMA”) protocol. Of course, many other protocols and cellular technologies exist which are equally applicable to embodiments of the present subject matter (e.g., World Interoperability Microwave Access (“WiMAX”), Long Term Evolution (“LTE”), GPRS, EDGE, W-CDMA, HSPA, Orthogonal Frequency Division Multiple Access (“OFDMA”) technologies, and Universal Mobile Telecommunications System (“UMTS”) technologies, and WiFi, to name a few) and such a disclosure should in no way limit the scope of the claims appended herewith.
Generally, a cellular communication system comprises a plurality of nodes (e.g., cell sites or base stations) positioned throughout a geographical region, a Mobile Telephone Switching Office (“MTSO”), plural mobile devices, etc. Each cell site generally includes a high power antenna system coupled to a transmitter and a receiver utilizing plural channels each comprised of forward control channels, reverse control channel, forward voice channels, and reverse voice channels. The MTSO may act as a central coordinating site for the entire cellular network. Of course, the MTSO may include various features, components and systems (e.g., geolocation systems, positioning determining equipment) and may be identified by other terms in different technologies.
When a subscriber initiates a call from a mobile device, a call initiation request is placed on a reverse control channel. If applicable, the mobile device may transmit its Mobile Identification Number (“MIN”) or other information (e.g., Electronic Serial Number, Station Class Mark, along with the destination telephone number. If a cell cite successfully receives this information, it is forwarded to the MTSO, which may verify subscriber registration and assigns the call to a forward and reverse voice channel pair. When a subscriber receives a call, the incoming call is received by the MTSO which may then direct each cell site to transmit on its FOCC a paging message containing the subscriber's MIN. Each mobile device constantly monitors the forward control channel and when its MIN is successfully detected, the mobile device transmits an acknowledgement signal on the reverse control channel. Upon a particular cell site receiving the acknowledgement signal, the MTSO directs that site to simultaneously issue a forward and reverse voice channel pair. In this manner, a conversation may be carried out on a dedicated channel pair separate from the control channels.
In order to monitor a cellular network's performance, detect fraudulent users, and troubleshoot problems, a service provider must be able to monitor the various control and voice channels. Monitoring real-time signals and signal to interference ratios at various locations in a service area is desirable and will allow a carrier to fine tune the network to improve its quality. Having drive or field testing capabilities that monitors all channels across multiple base station service areas and multiple technologies may provide the necessary data. Thus, there is an unmet need in the art to be able to quickly, accurately, and dynamically respond to perceived quality problems occurring within communication networks to be able to enhance quality of network services perceived by individual network users.
One embodiment of the present subject matter provides a method for blind determination processing of received signals. The method may comprise receiving RF signals from plural frequency bands and plural communication protocols in one or more receiver modules and downconverting the received signals into one or more common IF signals. The method may also comprise digitizing the one or more common IF signals, modifying IF signal bandwidth as a function of the plural communication protocols, and processing the modified signal in a processor without knowledge of the underlying plural communication protocols.
Another embodiment of the present subject matter may provide a method for processing signals based on a plurality of frequencies and protocols. The method may comprise receiving plural RF signals from plural frequency bands and plural communication protocols and converting one of the plural received RF signals into one or more common IF signals. The method may also comprise converting a second of the plural received signals into the one or more common IF signals and converting the one or more common IF signals into one or more baseband signals without knowledge of the underlying plural communication protocols.
One embodiment of the present subject matter may provide a receiver for receiving signals from plural frequency bands and plural communication protocols. The receiver may include an interchangeable RF front end having an A/D converter and an EEPROM having calibration data, wherein the RF front end receives RF signals from the plural frequency bands and said plural communication protocols. The receiver may also include IF circuitry producing one or more common IF signals from the received RF signals. A common digital back end may be provided for receiving digitized versions of the IF signals and modifying IF signal bandwidth as a function of the plural communication protocols, the back end having a host processor operatively connected to a host memory device via a host bus, one or more DSPs each operatively connected to at least one DSP memory device via a cluster bus, and an FPGA operatively connected to the host processor, the DSPs, a mezzanine bus, and the IF circuitry, wherein the FPGA receives the IF signal, modifies the IF signal bandwidth as a function of the plural communication protocols and determines a destination for the signal for processing where the destination is one of the one or more DSPs or the host processor, and sends the IF signal to the determined destination. The receiver may include a GPS receiver or a timing synchronization source for supplying timing signals to the RF front end and the common digital back end and may include a flash memory device operatively connected to the host bus for supplying configuration information.
Another embodiment of the present subject matter may provide a receiver for receiving signals from plural frequency bands and plural communication protocols. The receiver may include an interchangeable RF front end that receives RF signals from the plural frequency bands and communication protocols, IF circuitry producing one or more common IF signals from the received RF signals, digitizing the one or more common IF signals, wherein IF signal bandwidth changes as a function of the plural communication protocols. The receiver may also include a common digital back end for receiving the digitized versions of the IF signals and to process plural received signals without knowledge of the underlying communication protocols.
Yet a further embodiment of the present subject matter may provide a receiver for receiving signals from plural frequency bands and plural communication protocols, the receiver including modular RF circuitry having plural separate and selectable RF paths, each path having a predetermined frequency band. The receiver may also include IF circuitry having plural separate and selectable synthesizing paths, each synthesizing path corresponding to a selectable RF path. The receiver may include a converter for digitizing the IF signal, circuitry for modifying the digitized IF signal bandwidth as a function of the plural communication protocols, and common digital circuitry for receiving and processing the digitized IF signals, where components of the selectable RF and synthesizing paths are field-configurable as a function of the plural communication protocols.
An additional embodiment of the present subject matter provides a receiver for receiving signals from plural frequency bands and plural communication protocols, the receiver comprising modular RF circuitry having at least one separate and selectable RF path, the RF path having a predetermined frequency band. The receiver may also include IF circuitry having at least one separate and selectable synthesizing path, the synthesizing path corresponding to a selectable RF path. The receiver may also include a converter for digitizing the IF signal, circuitry for producing an digitized IF signal having a bandwidth changing as a function of the plural communication protocols, and common digital circuitry for receiving and processing the digitized IF signals, where components of the selectable RF and synthesizing paths are field-configurable as a function of the plural communication protocols.
These embodiments and many other objects and advantages thereof will be readily apparent to one skilled in the art to which the invention pertains from a perusal of the claims, the appended drawings, and the following detailed description of the embodiments.